Vapor barrier for a Pole Barn

Hi:
I will be building a Pole barn in SC. I want to use OSB composit panel sideing. The finished side looks like T 1-11. My pole barn will not be insulated & I would like to know if wraping my Pole barn first with a vapor barrier & then install the composite siding , or do I just install the siding over the girts. Im asking because I do not want to have a condensation problem inside the barn, and also since OSB gets killed from moisture, should I do this. Can't find any info on using a vapor barrier on the outside of a building. Also note that the OSB composit panels will be installed directly to the building's girts. There will be no other sideing except for the OSB panels. And I'm not talking about Tyvek here which is not a vapor barrier product. Im thinking more like the plastic sheeting used to seal off crawl space floors & foundations.
Thanks
Maddog1

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Vapor barrier for a Pole Barn

you are better off using a housewrap that lets the moisture inside the structure escape to the outside and keeps moisture from the outside out, like tyvek. I do not have much experience with the osb type t 1-11 but have installed lots of the hardie t 1-11 and real t 1-11 plywood. Because you are not putting sheathing on the wall before siding you may want to consider using the t 1-11 plywood because it is the thickest of the three and will help keep the building in rack.

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Vapor barrier for a Pole Barn

Hand Drive- Thanks for your thoughts on using Tyvek instead of a vapor barrier. Actually, I started thinking about it & I do think Tyvek would be better to allow the moisture passage in both directions. The pole building itself is only 18 feet by 24 feet & will have a total height of about 15 feet.
Attached to it will be a work shed 12 feet wide X 24feet long, same as the main building length. My thinking has been that this size building really does not need anything but the sideing on its frameing.

I built a pole barn 25 years ago with just the frameing & T-111. Twenty five years later, it's still standing & still square. I also need to save some money on the new one, so I'm opting to use the OSB panels right against the framing. Buiding is in South Carolina. Not to many issues here with iceing or snow loading. Some morning frost now & then & maybe a rare two or three inch snowfall that's usually gone in a day or two.

Vapor barrier for a Pole Barn

Quote:

Originally Posted by maddog1

Hand Drive- Thanks for your thoughts on using Tyvek instead of a vapor barrier. Actually, I started thinking about it & I do think Tyvek would be better to allow the moisture passage in both directions. The pole building itself is only 18 feet by 24 feet & will have a total height of about 15 feet.
Attached to it will be a work shed 12 feet wide X 24feet long, same as the main building length. My thinking has been that this size building really does not need anything but the sideing on its frameing.

I built a pole barn 25 years ago with just the frameing & T-111. Twenty five years later, it's still standing & still square. I also need to save some money on the new one, so I'm opting to use the OSB panels right against the framing. Buiding is in South Carolina. Not to many issues here with iceing or snow loading. Some morning frost now & then & maybe a rare two or three inch snowfall that's usually gone in a day or two.

Maddog1

A housewrap like Tyvek is certainly the way to go as plastic will trap and hold moisture in the structure. It will not matter what type of siding you use if you you sheath the walls beforehand, but if you do not sheath and rely on the siding as a lateral support solely then you will have to examine the structural aspects of the siding and determine if it will work from there.
The 5/8" t 1-11 siding would have plenty of lateral support if installed correctly. I'm not sure about the osb t 1-11 version but it is about 3/8" thick so may not be considered structural.